Plate-straining mechanism for use in printing machines



June 3, 1952 c. SEED 2,599,417

PLATE-STRAINING MECHANISM FOR USE IN PRINTING MACHINES Filed Sept. 1, 1948 3 Sheets-Sheet 1 1T I6 2 4L FIG. I. 8

ll 95 L 1 lNvsNrora M r B'Y W ATTOENEY.

PLATE-STRAINING MECHANISM FOR USE IN PRINTING MACHINES Filed Sept. I, 1948 L. C. SEED June 3, 1952 5 Sheets-Sheet 2 lNVENTOI? ATTORNE).

June 3, 1952 c. SEED 2,599,417

PLATE-STRAINING MECHANISM FOR USE IN PRINTING MACHINES Filed Sepb- 1948 3 Sheets-Sheet 5 m i u I\ .7 3

FIG]

INVENTOE BY W ATTORNE Y Patented June 3, 1952 Applieationse'ptember l, 1948,.Serial N6;,..4v,1s7r

IivGieat Britain September 3; 194'! 6.0laims. c 1

Thi inventionsrelates to mechanism to strain flexible printing plates: about the periphery of a. printingcylinder. In the specification 10f the pending; application" No..- 74739.12 is described and claimedrsuchaamechanism wherein the ends of .a. printing vplate i have secured to their under sunfa'oe'clamping bars which are introducedinto artlongitudinalor axial slotrwhere ribsron the bars are disposed to enter grooves zon-guide-comr ponentsrfixedl to the cylinder withinetherslots; the bars. y when in positionin the .slot, areurged towardsone another .in. a sense about the cylinder; by radially. displaceable pressure components which through" .wedge action are moved .to venease and then todi's'pldcethebars towardione another therib's on the .bars enteringth'e grooves to support the bars against being tiltedandiconqstraining-them to move tangentiallyn.

This arrangement! of mechanism is entirely satisfactory in many applicationsbut wh'erea maximum of the surface area. of va .platevisp required to be available to receive.matter,to. be printed; modification of .the arrangement is desired; Inthat'arrangement, the ribs and. grooves were disposed to move into cooperation: in a sensibly "tangential direction. and :hence .thefisldt inth'e cylinder .had to be made of "suflicient width to enablethe bars to be passed down radially to carry their-trips "into" register with the grooves,

whereafteritheyrwere brought'into cooperation by'th'e initial actuation of 'the pressure com.- ponents.

Now one feature of the present invention consists in so.f0rming the barsand 'th'egu'ide .comp'onents that the bars-are movable longitudinally of th'e cylinder to bririgtongues.iormedthereon into engagement with grooves on the guide com ponents Withthis arrangement whilethebars are stilliintroducedll.radially into themslo't to bring. them intoradial register with the pressure components, they-are then adjusted longitudinally, to bringthe tongues-intothe grooves in the. guidacomponents in readiness .for operation by the pressure components; This enables-wthe slot in the-cylinder to be considerably-reduced in width while still: retaining the asame= dimensions ofxthe parts, for it is not necessary for clearance in:..the:width:1oi "the .5101, "to be. provided f orrribs astformerlyt used; to "clear thec'guide icomponents in the circumferential sense-,rthis clearancabeing nowprovidediin the longitudinal sense.

The invention is illustrated in the accompanying: drawing inJWhich Figure l is "an end view "of apart: of .azprintingcylinder', Figure 2 a-longitudinazl sectional elevation-taken approximately 22 v on th'e lirie II-I-I Figure' 1, Figure=3 aplan vie'wiof figures various partsrremovedatdifferent points to expose other-parts", Figured-is mention on the line IV-JV-FigUr-d3F Figui e 5 Fa: section on the. line :Vt:--.F -Figure 3 and Fi'gure r6 ta-section orrthe -line Figure 3; Fi'guresni fifandllfi being.=to'/a' considerably largen-scalmhan l 'i'gure 3; Figures fl and m'a're respectively end and-'side elevations orszaz rmtmg plate40mm ifi'iQGEOFd ance': with th-isuinvention; and' showin "also parts cooperating: therewith. Figure 9 is =a 'di'ag rai-n mati'mplanand Figi-ire 10 a =perspecti vevviewof o'neoi the' component parts.=-

Referringta the-drawings; the -reference 1 in;- 'dicatesa: printing cylinder*'having: shaft ends 9.?01fil6il '0fi0l'l8610 athich isandicatd a l the cylinder form'e tli'rongh'out its" lengt with a": 516i; 3 l'iaving-a rl'atively narrow: mouth o ening to an enlargement li the'wallsof wliielr have inclinedafaces' 'at fii Fadjac'en-t tli'e n'ioutli;

Disposedlwith-i'n' :the" eniargementrszis a longn tudinally disposed: serisuof:ispaeediguideeblocks B-J'ea-ch havingza locating 'surfa'cetacand a groove 9 in onesof its zface's :which. is.-.=transversesto*tlre :lengthsof zthelslnt Msodahat thezopenings o'fiitliese grooves r9 Bare:directedetincthe dongiztud ihala sense of: the cylinder; ,thecdisposition' of .thesecblncks being:shownndiagrammaticallyinzEignre 9.1;

Thesprintinggplatet l o iis-eprovided', .asis surest cle'arlysshowmin Figures :7 :ands8r with bars: t I,

['2 :at each of-zitsiedgesg thesecbarstbeing'. secured as: by; welding rtoa the-sundersurfaceeofi ithe-zplate. Each bar is formed alon'gitsdengthk with bayonet slots: I3- at intervals corresponding rto' thecdispositionrot:therguidexblockssfi the'iislots sprbviding' tongueemember's I141: the: snr faces-soriwhich mate with the groovessi Theavidth ofiftheeopeningaoi :theibayonet "slants is such 5 thatt they; pass-. easily." oven" the: guide blocks 8 until thee transverseafaces l; lficof (the slots aseat zagainstrfixedelocatingrssnrfaces Ber-on these blockszs :ittwill:zbesclearrthat'ltozeifectfithis, the platenl0!istlaida:aboutztheccylindem: :and the=-two :bars I l'; 1 2 raresintr'oduced:.intbathesnpen .mouthofiithe slot 'idi. Thestonguesalhare now longitudinal: are'gisterrwithti thergroo ves 93in rth'e blnelrs': 8 aso thatby 'movingzthebars-.11 n n-(m s tudinally; inzzthe slot :4 theetong'ueszmemberssare moved: into'rthecgroovesdtoclock zthe 'zbars I I l 2 against 'centrifiug'ali actiontwhenrzthetcylindenrl lis' rotated.

Inorder to: move'rtheebar's a H .I 2-;towardszone anothenrsoaas to retrain the-:plate I lltaboutithe cylinder,;: i'.. e;? .tocmoveethe'e bars-J tangential '-senseaot ttheecylinderi-there r issprovidedcaeseries of pressure components I6 arranged in alternation at opposite sides of the enlargement 5. Each said component has a sloping surface to engage one or other inclined face 6 or I on the wall of the enlargement 5 and each pressure component I6 is shaped or cut away at I1 so as to leave a pressure face which is disposed to engage the relevant bar II or I2 closely behind its junction with the plate I0. Each pressure component I6 is extended by a wall I8 which is turned in to provide a flange I9 having an open-mouth slot 28. 1

The flange I 9 of each pressure component em braces an operating screw 2I (Figure 4) having a plain shank 22 seating snugly in a radial bore in a plug 23 in the cylinder I, the screw engaging a thread formed in the plug. The screw 2| is formed with flanges 24, 25 between which the flange I9 snugly extends and the screw is formed with a squared socket 26 to receive an operating key. The bars II, I2 are formed with opposed recesses 21 (Figure 3) to provide openings through which the key can be passed into the socket from outside the cylinder.

Hence, when a plate I9 has been wrapped about the cylinder I and the bars II and I2 have been moved longitudinally to carry their tongues l4 into the recesses 9 inthe blocks 8, the plate can be strained tightly about the cylinder by operating the various screws 2|. As the screws are rotated in one direction they move radially outwards of the cylinder I and so cause the various pressure components I6 also to move radially outwards. This movement causes the inclined face 8 or I to exert a wedge action on the adjacent pressure component I6 causing it to move into engagement with the associated bar II or I2 and then to thrust that bar towards the other bar and so to strain the plate.

It will be understood that the various operating screws'2l along the length of the cylinder will be actuated in turn in the manner described so that in the result the bars I I, I2 will be moved towards one another along their lengths.

The engagement between the tongues I4 on the bars I I, I2 and the grooves in the blocks 8 not only operates to hold the bars against centrifugal loading but also operates to hold the bars against any substantial tilting due to the application of pressure by the components I6, it being clear that during the movement of the bars II, I2, their tongues I4 will slide over the surfaces of the grooves 9 in the blocks 8.

In order to hold the plate I0 and its attached bars I I, I2 against longitudinal movement when once the tongues I4 on the bars have been moved into the grooves in the guide blocks 8 releasable or detachable positioning members 28 (Figures 2 and 3) can be fitted to the cylinder I to abut the ends of the bars.

The outer faces of the guide blocks 8 which form a support in the radial sense for the bars I I, I2, and the corresponding edges of the bars (and also the engaging faces of the tongues I4 and grooves 9) can be of part-cylindrical form centred about the axis of the cylinder; however as the straining movement is relatively small, a sufficiently close approximation to the circular movement can for all practical purposes be obtained by making those faces flat and tangential to the cylinder, as is shown in the drawings.

In addition to the guide blocks 8 intermediate supporting blocks 29 (Figures 8 and 2), can be provided to support the bars II, I2 at their free inner edges, these intermediate blocks being arranged in alternation with the guide blocks 8; here again the meeting faces of the bars and blocks can be either part cylindrical or tangential.

Each supporting block 29 can be formed at its outer or bar-supporting surface with a rib 98 (Figure 5) extending in the longitudinal sense of the cylinder. The ribs of the various blocks operate to position the bars I I, I2 centrally, i. e. in the sense axially of the cylinder, it being understood that each rib is positioned between the two guide bars; these ribs will also operate to assist in the plate straining operation for, as the pressure components I6 operate to apply pressure to the bars at a distance radially beyond the ribs 30, the ribs can function as a heel about which the bars will tend to rock. These ribs can if desired be rounded or tapered to assist in this action and two of the corners of the tongues I4 can be slightly backed-off for the same reason and also to facilitate the movement of the tongues longitudinally into the grooves 9.

The bars II, I2 can be secured as shown at the extreme ends of the plate I0 so that when the bars II, I2 are drawn together these ends abut or nearly so, or one bar can be secured within the corresponding end of the plate III so that this end (when the bars are drawn together) overlaps the other end.

The presure components I 6 can be arranged in alternation on opposite sides of the slot 4 throughout the entire length of the cylinder I but it is preferred as is shown to space them more closely at the ends of the cylinder and at the extreme ends of the cylinder the pressure components can be opposed to one another as shown in Figure 9.

It will now be clear that the width of the mouth 4 of the longitudinal gap in the cylinder I is governed only by the dimensions of the bars I I, I2 for the requisite mechanical strength and of the requisite movement of the bars towards one another to eifect satisfactory straining of the plate about the cylinder. The width of the slot can in consequence be relatively small so that very little of the circumferential surface of the cylinder is unavailable for printing; indeed, by arranging that the ends of the plate almost touch, it is only the very small longitudinal strip about the ends of the plate which could not be used to receive matter to be printed.

What I claim is:

1. In combination a printing cylinder having a longitudinal slot in its periphery, guide blocks in slot providing a series of fixed locating surfaces transverse to the length of the slot, a printing plate having bars secured at the undersurface of the plate at its ends, the said bars having a series of transverse locating surfaces and having endwise movement for locking engagement with the fixed locating surfaces and mechanism housed in said slot to urge the bars towards one another to strain the plate about the cylinder, the said mechanism comprising individually operable pressure components which are contained in the slot and disposed to engage remote faces of the said bars and are disposed to thrust the bars towards one another by wedge action, and operating screws positioned between the guide blocks to actuate the said pressure components.

2. In combination, a printing cylinder having a longitudinal slot, a flexible printing plate having bars secured to its ends at the undersurface of the plate, thesaid bars extending radially. into the slot, guide blocks disposed in a longitudinal series along the slot, the said blocks having locating surfaces disposed transversely of the slot and being formed for locking engagement by mating surfaces on the bars, a series of intermediate blocks supporting the bars between the guide blocks, pressure components arranged in the slot at each side of the bars, and means disposed in the slot to move the pressure components into engagement with the bars to move the bars towards one another.

3. In combination, a printing cylinder having a longitudinal slot, a flexible printing plate having bars secured to its ends at the undersurface of the plate, the said bars extending radially into the slot, guide blocks disposed in a longitudinal series along the slot, the said blocks having locating surfaces disposed transversely of the slot and being formed for locking engagement by mating surfaces on the bars, a series of intermediate blocks supporting the bars between the guide blocks, 7

a longitudinal series of pressure components disposed in the slot to engage the bars at remote faces thereof, and a corresponding series of operating screws to operate the pressure compo.- nents individually.

4. In combination, a printing cylinder having a longitudinal slot, a flexible printing plate having bars secured to its ends at the undersurface of the plate, the said bars extending radially into the slot, guide blocks disposed in a longitudinal series along the slot, the said blocks having locating surfaces disposed transversely of the slot and grooves for endwise locking engagement by mating surfaces on the bars, a longitudinal series of pressure components disposed in the slots to engage the bars at remote faces thereof, the said pressure components engaging inclined faces formed in the slot, and a series of radial operating screws positioned between the guide blocks to thrust the said pressure components against the inclined faces whereby the bars are thrust towards one another.

5. In combination, a printing cylinder having a longitudinal undercut slot in its periphery with walls having inclined faces, guide blocks in the slot and having fixed locating surfaces formed transversely to the length of the slot, a flexible printing plate having bars secured to its ends at the under surface of the plate, the said bars having transverse locating surfaces engaging the 10- cating surfaces on the guide blocks, means rendered effective by longitudinal movement of the bars, to interlock said bars with guide blocks engaged thereby, pressure components disposed in the slot for exerting pressure on one side of each bar and having sloping surfaces formed to engage the inclined faces of the walls of the slot, and operating screws positioned between the guide blocks for moving the pressure components to thrust the bars toward one another and thereby tighten the plate on the cylinder.

6. In combination, a printing cylinder having a longitudinal undercut slot in its periphery with walls having inclined faces, guide blocks in the slot and having fixed locating surfaces formed transversely to the length of the slot, a flexible printing plate having bars secured to its end at the under side of the plate, the said bars having transverse locating surfaces movably engaging the locating surfaces on the guide blocks, means rendered efifective by longitudinal movement of the bars, to interlock said bars with guide blocks engaged thereby, pressure components disposed in the slot for engagement with one side of each bar and formed with sloping surfaces for engaging the inclined faces on the walls of the slot, and operating screws positioned between the guide blocks for manipulating the pressure components to exert a wedge action between the bars and the inclined walls of the slot and thereby urge the bars toward one another.

LESLIE CHAMBERLAIN SEED.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date 1,582,390 Evans Apr. 27, 1926 1,662,284 Shea Mar. 13, 1928 2,056,991 Tomlin Oct. 13, 1936 

